1. Field of the Invention
The present invention relates to an electronic pulse generation device having a first electrode and a second electrode formed on an emitter element.
2. Description of the Related Art
In recent years, electronic pulse generation devices have electron emitters which have a cathode electrode and an anode electrode as a basic device. The electronic pulse generation devices have been used in various applications such as field emission displays (FEDs) and backlight units. When the electronic pulse generation devices are applied as the FEDS, a plurality of electron emitters are arranged in a two-dimensional array, and a plurality of phosphors are positioned at predetermined intervals in association with the respective electron emitters.
The conventional examples of the electronic pulse generation devices are disclosed in Japanese laid-open patent publication No. 1-311533, Japanese laid-open patent publication No. 7-147131, Japanese laid-open patent publication No. 2000-285801, Japanese patent publication No. 46-20944, and Japanese patent publication No. 44-26125, for example. All of these disclosed devices are disadvantageous in that since no dielectric material is employed in the emitter element, a forming process or a micromachining process is required between facing electrodes, a high voltage needs to be applied between the electrodes to emit electrons, and a panel fabrication process is complex and entails a high panel fabrication cost.
It has been considered to make an emitter element of a dielectric material. Various theories about the emission of electrons from a dielectric material have been presented in the documents: Yasuoka and Ishii, “Pulsed electron source using a ferroelectric cathode”, J. Appl. Phys., Vol. 68, No. 5, p. 546–550 (1999), V. F. Puchkarev, G. A. Mesyats, “On the mechanism of emission from the ferroelectric ceramic cathode”, J. Appl. Phys., Vol. 78, No. 9, 1 Nov., 1995, p. 5633–5637, and H. Riege, “Electron emission from ferroelectrics—a review”, Nucl. Instr. and Meth. A340, p. 80–89 (1994).
In the conventional example of the electronic pulse generation device, electrons trapped on the surface of the dielectric material, at the interface between the dielectric material and the upper electrode, and in the dielectric material by the defect level are released (emitted) when polarization reversal occurs in the dielectric material. The number of the electrons emitted by the polarization reversal does not change substantially depending on the voltage level of the applied voltage pulse.
However, the electron emission is not performed stably, and the number of emitted electrons is merely tens of thousands. Therefore, the conventional example of the electronic pulse generation devices are not suitable for practical use. Advantages of an electronic pulse generation device having an emitter element made of a dielectric material have not been achieved.